2. Peel the onions and cut them in half. Slice each half wafer thin there should be about 12 cups. In a large, heavy, ovenproof casserole or deep skillet, heat the butter and add the onions and garlic. Cook, stirring, until the onions are wilted and start to brown, about 10 minutes. Sprinkle with salt and pepper. Put the casserole in the oven and bake for 15 minutes.

3. Remove the casserole from the oven and sprinkle the onion mixture with flour, stirring to coat the onion pieces evenly. Add the water and wine and cook over high heat, scraping around the bottom and sides to dissolve the browned particles. Add the bay leaf and thyme and simmer for 30 minutes, stirring frequently.

4. Meanwhile, put the bread slices on a baking sheet and bake until brown and crisp.

5. Increase the oven temperature to 450F degrees

6. Fill 6 individual ovenproof soup tureens, or one large tureen, with the soup. If individual tureens are used, place 2 slices of toast atop the soup. if a large tureen is used, cover with the toast, overlapping. Sprinkle the toast with the Gruyere, then the Parmesan. place the Tureens on a baking dish to catch any drippings. Bake for about 10 minutes, or until the soup is piping hot, bubbling and brown on top.